Diesel Engine Parts, Products

1. Product Specifications

• OEM Part Number: 3938163
• Applicable Engine: Cummins 6BT 5.9L diesel engine (widely used for trucks, buses, construction machinery)
• Material: Alloy steel, forged & precision quenched and tempered for high wear resistance and structural strength
• Structure: Integral straight camshaft, equipped with intake cams, exhaust cams, journal bearings, timing gear mounting end and fuel pump drive eccentric
• Cam Quantity: 6 intake cams + 6 exhaust cams (for 6-cylinder inline engine)
• Machining Standard: Precision grinding on cam profile and shaft journals; surface carburizing hardening treatment
• Matching Parts: Timing gear, tappets, push rods, rocker arms, valves

2. Installation Position

This camshaft is installed inside the engine cylinder block, located below the cylinder head, parallel to the crankshaft:

1. It is seated in multiple bearing bores of the cylinder block, fixed by camshaft bearings;
2. The front end connects to the crankshaft timing gear via timing gears/timing chain;
3. The cam lobes face downward toward hydraulic tappets/mechanical tappets inside the engine block;
4. The rear end is fitted with a thrust plate to control axial clearance and prevent axial movement.

3. Main Functions

1. Control Intake & Exhaust Valve Timing Driven by the crankshaft through the timing transmission system, the camshaft rotates synchronously at half the crankshaft speed. The protruding cam lobes push tappets, push rods and rocker arms sequentially to open and close intake valves and exhaust valves accurately, completing air intake, exhaust and gas exchange for each cylinder in firing order.
2. Drive Diesel Fuel Injection Pump The eccentric segment on the camshaft drives the inline fuel injection pump, ensuring precise fuel injection timing matched with valve movement, which directly determines engine power output, fuel economy and exhaust emission performance.
3. Coordinate Engine Four-Stroke Cycle It precisely coordinates the four working strokes (intake, compression, power, exhaust) of each cylinder, guaranteeing the continuous and stable operation of the diesel engine.
4. Auxiliary Lubrication Matching Shaft journals cooperate with engine pressure lubrication system to bear cyclic load and friction during high-speed operation, supporting long-duration stable running of the engine.